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Archive for the ‘Electrical’ Category

Megohmmeters, more commonly known as “Megger Meters”

Thursday, May 7th, 2009

Megger has become the generic description for a high voltage, low current insulation tester. The word is short for megohm-meter.

Although any Ohmmeter or Multimeter may appear capable of similar measurements, only a Megger type instrument can test the quality of the insulation at or above its operating voltage.

Choice of test voltage is normally determined by the operating voltage of the circuit under test; usually twice the operating voltage is sufficient. Two basic insulation tests are possible: Insulation to ground and insulation between conductors.

Megohmmeters, more commonly known as “Megger Meters” are used to measure high insulation resistance. Megger has become the generic description for a high voltage, low current insulation tester. Ohmmeters and multimeters seem to be capable of similar measurements; however, only a Megger type instrument can test the quality of the insulation at or above its operating voltage. Two basic tests are possible; insulation to ground and insulation between conductors.

How Do Megohmmeters Work?

The megger consists of a DC generator and a direct reading ohm meter. The moving element of the ohm meter has two coils (A & B) which are firmly mounted to a pivoted central shaft and free to rotate over a C-shaped core. Flexible leads connect these coils. When current provided by the hand generator flows through Coil B, the coil will set itself at right angles to the field of the permanent magnet. When the test terminals open and an infinite resistance is given, no current flows in Coil A which causes Coil B to govern the motion of the rotating element, causing it to move in the extreme counter-clockwise position, which is marked as infinite resistance. The choice of test voltage is usually determined by the operating voltage of the circuit under test.

What are Safety Precautions When Using a Megohmmeter?

  • Never touch the test leads when the handle is being cranked
  • Always deenergize and discharge the circuit completely prior to connecting the meter
  • Use megohmmeters for high-resistance measurements only
  • When possible, disconnect what is being checked from other circuitry before using the meter

What Level of Voltage can a Megohmmeter Test?

The megohmmeter will test 100, 250, 500, 1000 or 2,500 Vdc, depending on the model.

What is the Difference between Analog and Digital Megohmmeters?

The difference lies in display and interface technologies. Analog meters display values on a dial, normally using a needle or pointer. Digital meters display results with a numeric readout.

What are Common Features of Megohommeters?

Megohmmeters can have remote controls to permit control by computers or other instruments. Some have built in calibration, allowing operators to calibrate test instruments without having to remove them from the testing location. Most meters have warning indicator lights that work with audible buzzers and alarms to indicate a pass or fail. Megohmmeters are often interfaced with programmable logic controllers. Output frequencies are also commonly available, and rapid cutoff circuitry to protect the device from extremely high levels of voltage or current.

What are Applications for Megohmmeters?

A variety of applications exist for this useful tool. Many meters are used to test the insulation resistance of wires, cables, transformers, and electrical motors. They can also be used to verify devices such as aircraft fuel pumps meet manufacturer IR specifications. Other electrical components can be tested as well, including cable reels, rectifiers and solid-state diodes.

Reduce costs, consumption and related emissions by 50 %

Thursday, April 9th, 2009

The On-Bill Financing (OBF) program works in conjunction with select SDG&E rebate and incentive programs, offering customers eligible to participate in those programs zero-percent financing for qualifying energy-efficient business improvements.

One such company offering this service is GreenLight Technology. Using the latest lighting technology, you can replace your inefficient parking lot, and exterior and interior building lighting and save as much as 60% in  energy cost and efficiency. Most lighting retrofit projects payback in 1 to 3 years. Greenlight Technology provides a comprehensive lighting retrofit installation plan and proposal, with all cost and benefits broken out, allowing you to make a well researched and sound decision.

The NEW Fluke 725 Multifunction Process Calibrator

Thursday, December 11th, 2008

Calibration instruments calibrate sensors and meters by using electrical signals or physical quantities.  AC voltage, DC voltage, AC current and DC current are common calibration signals.  Devices that produce electrical signals serve as meters for sensor calibration and send output signals to other devices.  Selecting calibration instruments requires an analysis of thermodynamic, environmental, process, electrical and physical properties.  The new powerful Fluke 725 Multifunction Process Calibrator will equip you with what you need to process almost any parameter.

The Fluke 725 measures and sources mA, volts, temperature (RTDs and thermocouples), frequency, ohms and pressure.  They do this by using optional pressure modules.  The split display will also let you view input and output values simultaneously.  For valve and I/P tests, you can source mA while measuring pressure.  This useful tool also has auto-stepping and auto-ramping for remote testing.  You will be able to support flow meter testing, frequency and CPM functions along with powering transmitters.  This process is done during a test using loop supply with simultaneous mA measurement.  Another great feature is the handling of fast pulsed RTD transmitters and PLCs, with pulses as short as 10ms.

Carrying the Fluke 725 with you is easy due to the small, streamlined shape.  It is one of the most durable and reliable calibrators on the market.  The screen is very easy to read and even has a backlight when working in darkness or poor light.  Memory options are useful for storing frequently used test setups.  This memory function allows for a fast set up.

Fluke Corporation is a world leader in the manufacture, distribution and service of electronic test tools and software. They have achieved the number one or number two position in every market they compete in. The Fluke brand has a reputation for portability, ruggedness, safety, ease of use and rigid standards of quality.  We highly recommend the Fluke 725 Multifunction Process Calibrator.   With the simple operation, broad testing options and rugged design, it will work as hard as you do.

Measure Insulation Resistance with a Megohmmeter

Sunday, November 30th, 2008

What is a Megohmmeter?

Megohmmeters, more commonly known as “Megger Meters” are used to measure high insulation resistance.  Megger has become the generic description for a high voltage, low current insulation tester.  Ohmmeters and multimeters seem to be capable of similar measurements; however, only a Megger type instrument can test the quality of the insulation at or above its operating voltage.  Two basic tests are possible; insulation to ground and insulation between conductors.

How Do Megohmmeters Work?

The megger consists of a DC generator and a direct reading ohm meter.  The moving element of the ohm meter has two coils (A& B) which are firmly mounted to a pivoted central shaft and free to rotate over a C-shaped core.  Flexible leads connect these coils.  When current provided by the hand generator flows through Coil B, the coil will set itself at right angles to the field of the permanent magnet.  When the test terminals open and an infinite resistance is given, no current flows in Coil A which causes Coil B to govern the motion of the rotating element, causing it to move in the extreme counter-clockwise position, which is marked as infinite resistance.  The choice of test voltage is usually determined by the operating voltage of the circuit under test.

What are Safety Precautions When Using a Megohmmeter?

* Never touch the test leads when the handle is being cranked

* Always deenergize and discharge the circuit completely prior to connecting the meter

* Use megohmmeters for high-resistance measurements only

* When possible, disconnect what is being checked from other circuitry before using the meter.

What Level of Voltage can a Megohmmeter Test?

The megohmmeter will test 100, 250, 500, 1000 or 2,500 Vdc, depending on the model.

What is the Difference between Analog and Digital Megohmmeters?

The difference lies in display and interface technologies.  Analog meters display values on a dial, normally using a needle or pointer.  Digital meters display results with a numeric readout.

What are Common Features of Megohommeters?

Megohmmeters can have remote controls to permit control by computers or other instruments.  Some have built in calibration, allowing operators to calibrate test instruments without having to remove them from the testing location.  Most meters have warning indicator lights that work with audible buzzers and alarms to indicate a pass or fail.  Megohmmeters are often interfaced with programmable logic controllers.  Output frequencies are also commonly available, and rapid cutoff circuitry to protect the device from extremely high levels of voltage or current.

What are Applications for Megohmmeters?

A variety of applications exist for this useful tool.  Many meters are used to test the insulation resistance of wires, cables, transformers, and electrical motors.  They can also be used to verify devices such as aircraft fuel pumps meet manufacturer IR specifications.  Other electrical components can be tested as well, including cable reels, rectifiers and solid-state diodes.

Hipot Testers

Wednesday, November 26th, 2008

Hipot” is an abbreviation for high potential (high voltage). A Hipot test, also called a Dielectric Withstand Test, checks for good isolation. A hipot tester is an electronic device that verifies the electrical insulation in a cable, transformer, electric motor, printed circuit board or any other wired assembly. This useful tool consists of a source of high voltage, current meter and a switching matrix to connect the high voltage source and the current meter to all of the contact points in a cable.

The main use for Hipot testers is to verify insulation of circuits. To accomplish this test, high voltage is applied between the circuits to verify a lack of current flow. A normal test should connect any circuit in common to ground. Then, the tester disconnects one circuit at a time and connects that circuit to high voltage. The flowing current is tested to make sure the level is low enough. Proper insulation is extremely important for safety and quality of electrical circuits.

The HT-2000 AC Hipot tester 0-2000V, up to 20mA is extremely affordable and user-friendly. One setup will conduct UL-CSA Ground continuity tests and the Hipot test, without a need for additional equipment. AC Hipot testing is best used for medical equipment in patient care areas, products that do not use Y capacitors, fixtures and portable lamps. This tester is also extremely easy to determine results; a green light means pass and a red light with a buzz means fail.

The HT-2800 DC Hipot tester 0=2800V, up to 5mA is extremely easy to operate. This tester conducts UL/CSA Ground continuity and DC Hipot tests with one setup. It will conduct in-depth by testing arc detection and leakage current. The HT-2800 performs the dielectric withstand and ground continuity production line tests required by UL and CSA. DC Hipot testing is best suited for computers, long cables or wires, products using Y capacitors for RFI supression, manufactured homes and telephone central station equipment.

The HTT-1 Hipot and Ground Continuity Function Checker was designed to be extremely reliable, safe and fast in verifying proper operation of Hipot and Ground Continuity Testers between calibration cycles. The user can check the result of the three failure modes encountered in production Hipot and ground circuit testing. These modes include open ground, high leakage current, and dielectric breakdown. The testing can be done separately or in any combination.

All three of these Hipot testers are manufactured by Compliance West USA. They each meet safety agency requirements by UL, CSA, TUV and CE for production line testing at unrivaled prices. They are ranked amidst the fastest and most accurate test equipment on the market.  Hipot testers are imperative to insure safety when working with energized circuits.

Facts About Digital Multimeters

Wednesday, November 26th, 2008

Digital Multimeters (DMM’s) Description:

Fluke 116

Fluke 116

A digital multimeter is a general-purpose measuring instrument that measures resistance, current and voltage. The meters measure electric current in ampere, volt and ohm. At times you will see multimeters listed as DMMs which simply stands for “Digital Multimeter.” In simpler terms, a DMM is an electronic tape measure for making electrical measurements. They were originally invented in the early 1920’s as radio receivers and other vacuum tube electronic devices became more common. In today’s world, almost all of the electronic products used in our personal and professional lives are built or serviced using multimeters. This handy tool can be a hand-held device useful for basic fault finding and field service work, or it can be used as a bench instrument which can measure to a very high degree of accuracy. Their main function is to troubleshoot electrical problems in a wide array of industrial and household devices such as batteries, motor controls, appliances, power supplies and wiring systems. Digital multimeters have a higher rate of accuracy compared to analog multimeters. The accuracy can be .5% compared to 3-5% for analog meters. It is extremely important to use a quality digital multimeter such as the Fluke 116 HVAC Digital True RMS Multimeter when diagnosing electrical problems.

How to Use a Digital Multimeter:

To measure voltage using a multimeter, plug the probes into the correct jacks on the multimeter. Black is negative and the red will go into the Volt/OHM/Temp jack. Do not put the red into the A or mA. When measuring AC voltage, switch the multimeter rotary switch to the V (wavy line). The reading will display when the probes are touched to the appropriate outlet or wire. When measuring DC voltage, the rotary dial needs to be turned to the V with a solid and broken line over it. When testing low voltage systems (less than 3VDC) use the mV setting. The result will display when the probes are touched to the appropriate area. When measuring resistance, follow the same directions; however, turn the rotary switch to the Ohm sign. Keep in mind the resistor’s rated value can be different than the measured value of a resistor in a circuit. Test leads can add .1% to .2% of error when measuring resistance. Testing the leads can be accomplished by touching the probe tips together and reading the resistance of the leads.

Safety When Using Multimeters:

To prevent the possibility of electric shock or injuries, never measure an in-circuit current when the open-circuit potential to earth is greater than 1000V. If the fuse blows during this type of measurement, the meter can easily be damaged and you have an extremely high risk of injury. It is imperative to check the meter’s fuses prior to measuring current and never to place the probes parallel to any circuit or component. Always use the correct function, range and terminals for all measurements. Remember, no tool by itself can guarantee absolute safety. The combination of the right tool and safe work practices will give you maximum protection. Use the following guidelines to increase safety when using a digital multimeter:

* Work on de-energized circuits when possible, also being careful to use lock-out/tag-out procedures. Always assume the circuite is live.

* Use insulated tools, wear safety glasses or a face shield and insulated gloves.

* Wear flame resistant clothing, and stand on an insulated mat.

* When making measurements on live circuits, hook on the ground clip first, then make contact with the hot lead. Hang or rest the meter when possible versus holding it in your hands.

* Use the three point test method; test a known live circuit, then the target circuit and finally test the target circuit again. This technique double checks that the meter worked properly before and after the measurement.

How to Choose a Multimeter:

The first thing to consider when shopping for a new multimeter is to analyze the worst-case scenario of your job. This will help to determine the category your use or application fits into. You will want to choose a meter that has a rating for the highest category you could be working in. Next, look for a multimeter with a voltage rating for the category that applies. Choosing the right digital multimeter requires evaluation of your basic measurement needs and job requirements, and looking at special features/functions built into the different types. Keep in mind the importance of test leads. The test leads need to be certified to as high or higher of a voltage and category than the meter. Also, look for multimeters and test leads with double insulation, recessed input jacks and test leads with shrouded input connectors. The main factors to consider include:

* Your work environment; voltage level, types of equipment, measurements and applications

* Specialty features/functions; capacitance, non-contact voltage, min-max record, data logging, trending, low impedance mode, frequency and temperature.

* Resolution and Accuracy; 6,000, 20,000 or 50,000 count resolution

Technology is changing rapidly and as electrical and electronic circuitry continues to get more complex, accurate diagnostic tools like digital multimeters are more important than ever. With the wide selection of features, choosing the right meter for the job can be challenging. Always keep safety the number one priority when using and choosing your next multimeter.

ESA – Arc Flash Analysis and Electrical Design Software

Wednesday, November 12th, 2008

EasyPower product family delivers a full lineup of powerful Windows®-based tools for intelligently designing, analyzing, and monitoring electrical power systems. With the fastest processing speeds on the market, EasyPower delivers instantaneous, accurate results to help you make more intelligent decisions.

  • Perform complex electrical engineering tasks
  • Detailed critical reports automatically
  • Eliminate dangerous and costly electrical hazards
  • Comply with NEC rules and ANSI standards

If their pre-configured packages don’t meet your specific needs, they allow you to build your own by selecting from a full menu of powerful options.

Watch this 3-minute EasyPower overview video!

Anna talks about Tic Tracer 300HV

Monday, October 6th, 2008

Why Use a Clamp Meter?

Tuesday, September 16th, 2008

Clamp meters allow for measurement of current, without needing to disconnect the wires where the measurement occurs.  By simply clamping the wire, you can get the measurement, and not cut the circuit.  When using a multitester or a digital multimeter, the circuit has to be cut.  In contrast, using a clamp meter, current can be measured by clamping a live wire over its sheath.  In addition to its simple operation, it allows safe measurement of a higher current.

Clamp meters feature low internal resistance and have both a positive and negative lead.  High current flow can indicate a short circuit, a defective component, or an unintentional ground.  Low current flow can indicate high resistance, or poor current flow within the circuit.  Both types of clamp meters (digital and analog) are designed to measure levels of direct current (DC) and alternating current (AC).  Most products have built in sensors.  Some clamp meters can test diodes or transistors while others can monitor thermocouples or resistance temperature detector (RTD) values.  Some may adjust sampling rates automatically, display status information as a bar graph, and measure decibel (dB) readings.  Our specialty clamp meters provide special measurement types and optional features. Some can test diodes or transistors. Others can monitor thermocouples or resistance temperature detector (RTD) values. Programmable clamp meters provide internal data storage and will allow you to establish activation triggers.  Clamp meters are extremely useful and allow for many types of safe electrical testing.

Thermographer and Rubber Insulated Arc Flash Gloves

Sunday, September 14th, 2008

Insulating rubber gloves are one of the most important articles of personal protection for electrical workers.

Combining high dielectric and physical strength, flexibility and durability, Texso’s insulating rubber gloves are the superior performance meeting and exceeding the requirements of current ASTM D120 specifications and NFPA 70E standards.

Texso offers some of the most complete selection of gloves.

Texso recommends testing all gloves to assure they meet OSHA and ASTM requirements.

If your not sure what gloves you need you can call us direct (760) 444-0032.

Thermographer Arc Flash Gloves

All the materials and threads used in the construction of the Thermographer Gloves are inherently flame resistant (FR). We carry the unique Oberon Thermographer Gloves that provide the highest level of flash protection in the market for gloves.

STANDARDS: Complies with NFPA 70E-2004. Tested according to ASTM F1959-04.

SIZES: Regular and Large, specify size when ordering.

Rubber Insulating Gloves

We also offer 100% natural rubber, smooth finish gloves. Available as single items or in complete kits (Rubber Glove, Leather Protector and Glove Bag).

  • Class 00 (500 Volts)
  • Class 0 (1000 Volts)
  • Class 1 (7500 Volts)
  • Class 2 (17000 Volts)

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